Braking systems such as those used to retard the motion of all manner of wheeled transportation vehicles come in many forms. The brake systems are most typically of a drum or disk configuration with a shoe or pad made of abrasive material acting on the drum or disk, respectively, to produce a friction derived braking force. Application of the shoe or pad is usually accomplished by the application of force, in the form of pressure, to press an abrasive face of the shoe or pad against the drum or disk.
In early brake systems the force pressing on the shoe or pad was applied mechanically using mechanical advantage (leverage) to augment the brake force applied by the vehicle operator at the operator interface (usually a brake pedal). Later systems used a hydraulic circuit to convert operator input to a hydraulic force acting on the braking components. Numerous approaches have been developed to augment the operator input to the brake system in order to provide additional energization (applied force) of the braking components. These approaches include vacuum assist, pump-generated hydraulic assist, electric servo assist, pump-generated air pressure assist and other similar approaches.
Despite the fact that a braking system is an essential and critical component of most transportation vehicles, the braking systems in common use are quite complex, expensive to manufacture, and require regular and costly maintenance due to their complexity and the use of friction as the primary mechanism for generating braking forces.
What is needed is a self energizing braking system that is simple and that has a low maintenance requirement.